OFFSET
0,1
LINKS
T. D. Noe, Table of n, a(n) for n=0..200
Quynh Nguyen, Jean Pedersen, and Hien T. Vu, New Integer Sequences Arising From 3-Period Folding Numbers, Vol. 19 (2016), Article 16.3.1. Cites this sequence.
FORMULA
a(n) = (2^(8*n) - 1)/(2^n - 1). Exp( Sum_{n >= 1} a(n)*x^n/n ) = 1 + 255*x + 43435*x^2 + ... is the o.g.f. for the 7th subdiagonal of triangle A022166, essentially A022190. - Peter Bala, Apr 07 2015
MATHEMATICA
Total[#^Range[0, 20]&/@Divisors[128]] (* Vincenzo Librandi, Apr 17 2014 *)
PROG
(Magma) [DivisorSigma(n, 128): n in [0..20]]; // Vincenzo Librandi, Apr 17 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved